gtk2/gdk/gdkpixbuf-render.c
Federico Mena Quintero 25a8142429 #include <config.h>, and fix includes.
1999-12-02  Federico Mena Quintero  <federico@redhat.com>

	* src/testpixbuf.c: #include <config.h>, and fix includes.

	* src/testpixbuf-drawable.c: #include <config.h>, and fix includes.

	* src/io-xpm.c: Fix includes.

	* src/io-tiff.c: Fix includes.

	* src/io-ras.c: Fix includes, and do not include more stuff than needed.

	* src/io-pnm.c: Fix inlcudes, and do not include more stuff than needed.

	* src/io-png.c: Fix includes.

	* src/io-ico.c: Fix includes, and do not include more stuff than needed.

	* src/io-gif.c: Fix includes, and do not include more stuff than needed.

	* src/io-bmp.c: Fix includes, and do not include more stuff than needed.

	* src/gnome-canvas-pixbuf.c: Fix includes.

	* src/gdk-pixbuf.c: Fix includes.

	* src/gdk-pixbuf-util.c: Fix includes.

	* src/gdk-pixbuf-render.c: Fix includes.

	* src/gdk-pixbuf-io.h: Fix includes.

	* src/gdk-pixbuf-drawable.c: Fix includes.

	* src/gdk-pixbuf-drawable.h: Use angle brackets for the gdk-pixbuf
	include files.

	* src/gdk-pixbuf-data.c: Fix includes.

	* src/gdk-pixbuf-loader.c: #include <config.h>

	* src/gdk-pixbuf-loader.h: Use angle brackets for the gdk-pixbuf
	include files.

	* src/Makefile.am: Commented out the gdk-pixbuf-drawable stuff,
	since it is not finished.
1999-12-02 20:44:43 +00:00

323 lines
9.7 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* GdkPixbuf library - Rendering functions
*
* Copyright (C) 1999 The Free Software Foundation
*
* Author: Federico Mena-Quintero <federico@gimp.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <config.h>
#include <gdk/gdk.h>
#include <libart_lgpl/art_rect.h>
#include "gdk-pixbuf.h"
/**
* gdk_pixbuf_render_threshold_alpha:
* @pixbuf: A pixbuf.
* @bitmap: Bitmap where the bilevel mask will be painted to.
* @src_x: Source X coordinate.
* @src_y: source Y coordinate.
* @dest_x: Destination X coordinate.
* @dest_y: Destination Y coordinate.
* @width: Width of region to threshold.
* @height: Height of region to threshold.
* @alpha_threshold: Opacity values below this will be painted as zero; all
* other values will be painted as one.
*
* Takes the opacity values in a rectangular portion of a pixbuf and thresholds
* them to produce a bi-level alpha mask that can be used as a clipping mask for
* a drawable.
*
**/
void
gdk_pixbuf_render_threshold_alpha (GdkPixbuf *pixbuf, GdkBitmap *bitmap,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
int alpha_threshold)
{
ArtPixBuf *apb;
GdkGC *gc;
GdkColor color;
int x, y;
guchar *p;
int start, start_status;
int status;
g_return_if_fail (pixbuf != NULL);
apb = pixbuf->art_pixbuf;
g_return_if_fail (apb->format == ART_PIX_RGB);
g_return_if_fail (apb->n_channels == 3 || apb->n_channels == 4);
g_return_if_fail (apb->bits_per_sample == 8);
g_return_if_fail (bitmap != NULL);
g_return_if_fail (src_x >= 0 && src_x + width <= apb->width);
g_return_if_fail (src_y >= 0 && src_y + height <= apb->height);
g_return_if_fail (alpha_threshold >= 0 && alpha_threshold <= 255);
gc = gdk_gc_new (bitmap);
if (!apb->has_alpha) {
color.pixel = (alpha_threshold == 255) ? 0 : 1;
gdk_gc_set_foreground (gc, &color);
gdk_draw_rectangle (bitmap, gc, TRUE, dest_x, dest_y, width, height);
gdk_gc_unref (gc);
return;
}
color.pixel = 0;
gdk_gc_set_foreground (gc, &color);
gdk_draw_rectangle (bitmap, gc, TRUE, dest_x, dest_y, width, height);
color.pixel = 1;
gdk_gc_set_foreground (gc, &color);
for (y = 0; y < height; y++) {
p = (apb->pixels + (y + src_y) * apb->rowstride + src_x * apb->n_channels
+ apb->n_channels - 1);
start = 0;
start_status = *p < alpha_threshold;
for (x = 0; x < width; x++) {
status = *p < alpha_threshold;
if (status != start_status) {
if (!start_status)
gdk_draw_line (bitmap, gc,
start + dest_x, y + dest_y,
x - 1 + dest_x, y + dest_y);
start = x;
start_status = status;
}
p += apb->n_channels;
}
if (!start_status)
gdk_draw_line (bitmap, gc,
start + dest_x, y + dest_y,
x - 1 + dest_x, y + dest_y);
}
gdk_gc_unref (gc);
}
/* Creates a buffer by stripping the alpha channel of a pixbuf */
static guchar *
remove_alpha (ArtPixBuf *apb, int x, int y, int width, int height, int *rowstride)
{
guchar *buf;
int xx, yy;
guchar *src, *dest;
g_assert (apb->n_channels == 4);
g_assert (apb->has_alpha);
g_assert (x >= 0 && x + width <= apb->width);
g_assert (y >= 0 && y + height <= apb->height);
*rowstride = 4 * ((width * 3 + 3) / 4);
buf = g_new (guchar, *rowstride * height);
for (yy = 0; yy < height; yy++) {
src = apb->pixels + apb->rowstride * (yy + y) + x * apb->n_channels;
dest = buf + *rowstride * yy;
for (xx = 0; xx < width; xx++) {
*dest++ = *src++;
*dest++ = *src++;
*dest++ = *src++;
src++;
}
}
return buf;
}
/**
* gdk_pixbuf_render_to_drawable:
* @pixbuf: A pixbuf.
* @drawable: Destination drawable.
* @gc: GC used for rendering.
* @src_x: Source X coordinate within pixbuf.
* @src_y: Source Y coordinate within pixbuf.
* @dest_x: Destination X coordinate within drawable.
* @dest_y: Destination Y coordinate within drawable.
* @width: Width of region to render, in pixels.
* @height: Height of region to render, in pixels.
* @dither: Dithering mode for GdkRGB.
* @x_dither: X offset for dither.
* @y_dither: Y offset for dither.
*
* Renders a rectangular portion of a pixbuf to a drawable while using the
* specified GC. This is done using GdkRGB, so the specified drawable must have
* the GdkRGB visual and colormap. Note that this function will ignore the
* opacity information for images with an alpha channel; the GC must already
* have the clipping mask set if you want transparent regions to show through.
*
* For an explanation of dither offsets, see the GdkRGB documentation. In
* brief, the dither offset is important when re-rendering partial regions of an
* image to a rendered version of the full image, or for when the offsets to a
* base position change, as in scrolling. The dither matrix has to be shifted
* for consistent visual results. If you do not have any of these cases, the
* dither offsets can be both zero.
**/
void
gdk_pixbuf_render_to_drawable (GdkPixbuf *pixbuf,
GdkDrawable *drawable, GdkGC *gc,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
GdkRgbDither dither,
int x_dither, int y_dither)
{
ArtPixBuf *apb;
guchar *buf;
int rowstride;
g_return_if_fail (pixbuf != NULL);
apb = pixbuf->art_pixbuf;
g_return_if_fail (apb->format == ART_PIX_RGB);
g_return_if_fail (apb->n_channels == 3 || apb->n_channels == 4);
g_return_if_fail (apb->bits_per_sample == 8);
g_return_if_fail (drawable != NULL);
g_return_if_fail (gc != NULL);
g_return_if_fail (src_x >= 0 && src_x + width <= apb->width);
g_return_if_fail (src_y >= 0 && src_y + height <= apb->height);
/* This will have to be modified once libart supports other image types.
* Also, GdkRGB does not have gdk_draw_rgb_32_image_dithalign(), so we
* have to pack the buffer first.
*/
if (apb->has_alpha)
buf = remove_alpha (apb, src_x, src_y, width, height, &rowstride);
else {
buf = apb->pixels + src_y * apb->rowstride + src_x * 3;
rowstride = apb->rowstride;
}
gdk_draw_rgb_image_dithalign (drawable, gc,
dest_x, dest_y,
width, height,
dither,
buf, rowstride,
x_dither, y_dither);
if (apb->has_alpha)
g_free (buf);
}
/**
* gdk_pixbuf_render_to_drawable_alpha:
* @pixbuf: A pixbuf.
* @drawable: Destination drawable.
* @src_x: Source X coordinate within pixbuf.
* @src_y: Source Y coordinates within pixbuf.
* @dest_x: Destination X coordinate within drawable.
* @dest_y: Destination Y coordinate within drawable.
* @width: Width of region to render, in pixels.
* @height: Height of region to render, in pixels.
* @alpha_mode: If the image does not have opacity information, this is ignored.
* Otherwise, specifies how to handle transparency when rendering.
* @alpha_threshold: If the image does have opacity information and @alpha_mode
* is GDK_PIXBUF_ALPHA_BILEVEL, specifies the threshold value for opacity
* values.
* @dither: Dithering mode for GdkRGB.
* @x_dither: X offset for dither.
* @y_dither: Y offset for dither.
*
* Renders a rectangular portion of a pixbuf to a drawable. This is done using
* GdkRGB, so the specified drawable must have the GdkRGB visual and colormap.
*
* When used with #GDK_PIXBUF_ALPHA_BILEVEL, this function has to create a bitmap
* out of the thresholded alpha channel of the image and, it has to set this
* bitmap as the clipping mask for the GC used for drawing. This can be a
* significant performance penalty depending on the size and the complexity of
* the alpha channel of the image. If performance is crucial, consider handling
* the alpha channel yourself (possibly by caching it in your application) and
* using gdk_pixbuf_render_to_drawable() or GdkRGB directly instead.
**/
void
gdk_pixbuf_render_to_drawable_alpha (GdkPixbuf *pixbuf, GdkDrawable *drawable,
int src_x, int src_y,
int dest_x, int dest_y,
int width, int height,
GdkPixbufAlphaMode alpha_mode,
int alpha_threshold,
GdkRgbDither dither,
int x_dither, int y_dither)
{
ArtPixBuf *apb;
GdkBitmap *bitmap = NULL;
GdkGC *gc;
g_return_if_fail (pixbuf != NULL);
apb = pixbuf->art_pixbuf;
g_return_if_fail (apb->format == ART_PIX_RGB);
g_return_if_fail (apb->n_channels == 3 || apb->n_channels == 4);
g_return_if_fail (apb->bits_per_sample == 8);
g_return_if_fail (drawable != NULL);
g_return_if_fail (src_x >= 0 && src_x + width <= apb->width);
g_return_if_fail (src_y >= 0 && src_y + height <= apb->height);
gc = gdk_gc_new (drawable);
if (apb->has_alpha) {
/* Right now we only support GDK_PIXBUF_ALPHA_BILEVEL, so we
* unconditionally create the clipping mask.
*/
bitmap = gdk_pixmap_new (NULL, width, height, 1);
gdk_pixbuf_render_threshold_alpha (pixbuf, bitmap,
src_x, src_y,
0, 0,
width, height,
alpha_threshold);
gdk_gc_set_clip_mask (gc, bitmap);
gdk_gc_set_clip_origin (gc, dest_x, dest_y);
}
gdk_pixbuf_render_to_drawable (pixbuf, drawable, gc,
src_x, src_y,
dest_x, dest_y,
width, height,
dither,
x_dither, y_dither);
if (bitmap)
gdk_bitmap_unref (bitmap);
gdk_gc_unref (gc);
}